I want to detect when my piece is stopped, however when it is stopped the number that I get from the sensor in all the axis is not "0" and always change.

Not sure that I understand your problem correctly, but you might want to look at the amount of change in the sensor readings, or the delta values (subtracting the current from the previous and take the absolut value). If for 3 seconds (delay object) they stay below a certain threshold (trial and error), then light the applaus sign. The best sensor however to detect if your piece is finished is you, of course.

I know you got it working, that’s great. However you might want to search for "smoothing sensor values", which may be helpful in the future. There are a number of good example patches for this problem, which comes up using many different sensors… the values coming in are jittery by nature, so there are a bunch of ways to smooth them out and make them more useful.